(a) Field
The invention relates to a display device and a manufacturing method thereof
(b) Description of the Related Art
As a display device, a flat panel display may be used. The flat panel display includes a liquid crystal display (“LCD”), an organic light emitting diode display (“OLED”), a plasma display, an electrophoretic display, and an electrowetting display, for example.
Among the various flat panel displays, an LCD is one of the flat panel displays which have been most widely used and generally includes two sheets of display panels in which field generating electrodes, such as a pixel electrode and a common electrode, are formed and a liquid crystal layer interposed therebetween. The LCD further includes a backlight unit which provides light to the display panels having the liquid crystal layer interposed therebetween. The LCD displays an image by applying a voltage to the field generating electrode to generate an electric field in the liquid crystal layer, determining an orientation of liquid crystal molecules of the liquid crystal layer based on the generated electric field, and controlling emission of light provided by the backlight unit.
Generally, the display device including the LCD includes a thin film transistor (“TFT”) array panel. The TFT array panel includes a gate electrode which is a portion of a gate wire, a semiconductor layer providing a channel, and a source electrode which is a portion of a data wire and a drain electrode. A TFT is a switching element which transfers or blocks an image signal transferred through the data wire to or from the pixel electrode depending on a scanning signal transferred through the gate wire.
To confirm whether progress results of each of the processes in a process of manufacturing a display device are correct, a thickness, resistance, a concentration, a pollution level, and a critical dimension of results of each process, electrical characteristics of elements, and the like are measured. Since it is likely to damage elements during the measuring process, there is a case in which an actual substrate may not be monitored during the process.
In this case, a pattern called a test element group (“TEG”) is formed in a specific portion of the substrate on which the elements are formed or a separate test area to perform processes on the substrate on which the actual elements are formed and measure the TEG, thereby evaluating the corresponding processes and the characteristics of the elements.